Loaded electric conductor



. Nov. 13, 1928. 1,691,309

W. 5. SMITH ET AL LOADED ELECTRIC CONDUCTOR Filed Nov. 17, 1926 INVENTORS S. SMITH,

w. H. J. GABNETT, AND J. A. HOLDEN,

ney

Patented Nov. 13, 1928 entree STAT ES PATENT OFFICE.

WILLOUGI-IBY STATHAM SMITH, or nnNoniAMs, nnwroiv POPPLEFORD; HENRY aosnrn eannn r'r, or SEVENOAKS; arm some ANGEL nonnnn, or GIDEA PARK,

ENGLAND.

LOADED ELECTRIC CONDUCTOR.

Application filed November 17, 1926, Seria1 No. 149,007. and in Great Britain September 25, 19:26.

This invention relates to loaded GODClUC- tors, and more particularly to conductors of the kind commonly employed in telegraphy and telephony, in which the loading is provided in the form of a wire or tape of magnetic material wound uponthe conductor. Such conductors are usually subjected to a processof annealing after having been wound with the wire or tape in order that the required magnetic propert'es may be developed in the loading material.

l fe have found, however, that when a conductor has been whipped at very high speed with, say, a hard drawn loading wire.

or tape, the required magnetic properties are apt not to be developed by the subsequent annealing process owing to the fact that the said loadlng wire or tape tends to grip the conductor proper to an extent suflicient to leave itself in a more or less highly strained condition, even after annealing. 7

According to this invention a spacing wire or the like, made of a materlal whose fusing temperature is not greater than the temperature at which the annealing process is carried out, is laid under the loading wire. or tape so that during the annealing process the spacing wire fuses and so relieves the tension of the loading material.

The metal or alloy forming the spacing wire or the like must be such as'will, on

fusing, not injure or embrittle the conductor proper, and a copper-silver alloy of the composition silver and 40% copper has been found particularly suitable for the pur pose. Thediameter of the spacing wire may be varied to suit various requirements, though it has been found that two thousandths of an inch is suitable in most cases.

The spacing wire may conveniently be laid approximately in a straight line along the copper conductor and may be attached in a suitable manner at the beginning of each length, but this not essential. the loading wire (or tape) from sticking to the spacing wire during annealing, a slight oxidized loading wire (or tape) is prefer-' ably used.

The invention is diagrammatically illustrated in the accompanying drawings, in which Figures 1 and 2 are respectively half sectional views of a loaded conductorbefore and after annealing. In the drawings a indicates the conductor and Z) the loading ma- To prevent terial. Referring to Figure ,1, the spacing wire 5 s shown at a and around which is an area denoted by the letter a3.v Referring now to Figure 2, which shows the loaded conductor after passage through the furnace, the spacing wire no longer exists in the form shown in Figure l, but has melted and diffused into the copper of 'the conductor a forming a thin film and leaving an air space e ovcrpthe film. It will he notedthat the area 0 in Figure 2 is. less than the area a? in Figure l, with the result that a slight loosen ing takes. place in the loading material It should be understood that the view of the conductor in Figure 2 showsit-in an intermediate stage, i. e. immediately after heat treatment and before it has cooled. During cooling, the loading wire or material 6 will further contract until the area 0 no longer remains.

What we claim is 1. A method for the manufacture of loaded conductors which require heat treatment to develop the required magnetic properties,

which comprises laying a metal spacer fusible at a temperature not exceeding the temperature for annealing the loading upon the which comprises laying a meal spacer composed of a ESllVGIrCOPPGI alloy andfusible at a temperature not exceeding the tempera ture for annealing the loading upon the conductor, winding the loading material over the conductor and the metal spacer and subjectingthe loaded conductor to the said heat treatment which causes the metal spacer to melt. V

3. A method for-the manufacture of loaded conductors which require heat treatment to develop the required magnetic properties, which comprises laying a metal spacer composed of a silver-copper alloy containing 60% silver and l0% copper and fusible at a tentiperature not exceeding the temperature for annealing the loading upon the conductor, winding the loading material over the conductor and the metal spacer and subjecting the loaded conductor to the said heat treatment Which causes the'metal spacer to melt. i i

. 4:. A method for the manufacture'ot loaded conductors which require heat treatment ed conductors which require heat treatment to develop the required magnetic properties, which comprises laying a metal spacer 1/2000ths of an inch thick and fusible at a temperature not exceeding he temperature for annealing the loading upon the conductor, Winding the loading material over the conductor and the metal spacer and subjecting the loaded conductorto the said heat treat ment which causes the metal spacer to melt' 6. A method for the manufacture of loaded conductors which require heat treatment to develop the required magnetic properties, which comprises laying ametal spacer fusible at a temperature not exceeding the temperature for annealing the loading upon the conductor, vinding a superficiallyoxidized loading mat "al over the conductor and the metal spacer and subjecting the loaded conductor to the said heat treatment Which causes the metal spacer to melt '1 A method for the manufacture of loadcopper conductors Which require heat reatmcnt to develop the required magnetic rop rties. Whichcomprises laying a metal v p V posed of a silver-copper alloy and s fusible at a temperature not exceeding the nperature for annealing the loadingupon t conductor, Winding the loading material the conductor and th metalspacer and sulfectinp; the heat treatment,- spac rte melt.

In testimony that We claim the foregoing our invention, we have signed our names this 29th day of October, 1926.

Elli-ill GHBYSTATEAM SMITL. FER-Y JGSEPH GARNETT. JOHN ANGEL HOLDEN.

Which causes the metal loaded conductor to the said 

